Republic XF-84H Thunderscreech
Template:Infobox Aircraft The Republic Aviation Company XF-84H Thunderscreech was an American-built turboprop experimental fighter. Part of the XF-84 series of Aeroplanes, It is unique among them in that it was driven by a supersonic propellor rather than a straight jet engine. It was originally designated the XF-106 due to its radical diferences to the rest of the XF-84 series.
It was powered by an Allison XT-40 jet engine with afterburner, capable of 5850 horsepower. The afterburner was never lit.
The propellor was a square blade, constant speed supersonic propellor, turning at 3000 rpm, with the tips of the blades travelling at approximately mach 1.18, Thrust was adjusted by changing the blade pitch.
It was the first plane to carry a Ram Air Turbine. This turbine would automatically swing out into the air stream to provide extra hydraulic and electrical power.
Only two (RS-059 and RS-060) were ever made and only the RS-059 ever flew, logging only 10 hours.
RS-059 (pictured) was retired and spent many years mounted on a pole outside Meadows Field Airport, Bakersfield, California. Carefully removed, the plane went to the 178th Fighter Wing of the Ohio Air National Guard whose volunteers spent over 3000 hours bringing the Thunderscreech back into display condition. It is now on show at the USAF Museum
RS-060 (currently unknown)
It appears in the Guiness book of records as the fastest propellor driven plane ever built, with a design top speed of 670 m/ph, it is unofficailly reported to have reached 623 m/ph.
As a postscript to that record, it is almost always also refered to as possibly the loudest propellor plane ever built. They were Extremely loud, hence the nickname thunderscreech, and were reportedly audible 25 miles away. Nearby, standard ear protectors "made no difference".
Due to the nature of the massive torque from the propellor, handling was reportedly "difficult". One test pilot flew in it once and refused to ever fly in it again. Another encountered 10 "emergencies" of varying degrees during his 11 test flights in it.
It was only ever flown by the Republic test pilots, making it possibly the only USAF plane to be never flown by a USAF pilot.